This is a blog about bridge -- everyday comments on stuff that happens at the table -- or theory.

Sunday, October 30, 2016

Web movements for teaching

One of my wife Kim's bridge classes includes a duplicate every other week. With discussion about the hands, there is only time to play 6 boards. The number of tables varies usually between nine and twelve. Any multiple of three tables can easily be accommodated with the appropriate number of sections, each with a straight Mitchell movement. But what about ten and eleven tables? These can be handled with either two sections of three tables and a section of four; or two sections of four, with a section of three. The trouble is those four-table sections! There's no Mitchell variation that I have found to work for this type of situation (having single-board rounds is not very appealing). I therefore turned to the "web" movement.

The so-called web movement is the invention of former National director John "Spider" Harris in the 1970s. For a full description of web movements, the best source is Tim Hill's document. In a web movement with an even number of tables, as we have here, a section is split into two sub-sections each comprising half of the tables. The second of these sub-sections is boarded "backwards" which is the insight that Spider Harris came up with to make the movement work.

This is how the movement unfolds for one four-table section:

Four Table Web

Round 1

Round 2

Round 3

Table 1 (N/S 1)

E/W 1 playing boards 1,2

E/W 4 playing boards 3,4

E/W 3 playing boards 5,6

Table 2 (N/S2)

E/W 2 playing boards 3,4

E/W 1 playing boards 5,6

E/W 4 playing boards 1,2

1-2 Bye-stand

boards 5,6

boards 1,2

boards 3,4

Table 3 (N/S 3)

E/W 3 playing boards 1,2

E/W 2 playing boards 5,6

E/W 1 playing boards 3,4

Table 4 (N/S 4)

E/W 4 playing boards 5,6

E/W 3 playing boards 3,4

E/W 2 playing boards 1,2

3-4 Bye-stand

boards 3,4

boards 1,2

boards 5,6

Of course, as you can see, you need two sets or "cases" of boards (i.e. twelve boards in all). That's the drawback to the web movement (and the reason directors have never really liked to use it until recently). Now, however, that we have dealing machines available, it becomes much less of a burden for the director (or teacher in this case) to set up a web movement.

The other advantage is that, once the boards are put into position, the movement pretty much runs itself. Some of the other alternative movements require changing the movement half-way through, having relays, and so on. These can be somewhat problematic when the players are relatively new to duplicate bridge.

So, as you can see, the web movement isn't only for large single sections, as typically used in tournaments in New England. It can be used any time the number of boards in play is insufficient to cover all the tables in a section.